Explosively actuated fastening tool



Se t. 8, 1970 J. E. JACKSON ET EXPLOSIVELY ACTUATED FASTENING TOOL 2 sheets-sheet 1 Filed Oct. 31. 1966 A\\A..... v \M 5 u m .imwx

6 m @mm ml Q sw /N VENT 0R5 JOHN EJACKSON JAMES E BOEHM A T'TORNEYS Se t. 8, 1970 J E. JACKSON ET AL 3,527,395

EXPLOSIVELY ACTUATED FASTENING TOOL Filed Oct. 31. 1966 2 Sheets-Sheet 2 //V VEN TORS JOHN E. JACKSON JAME8 F EOE/1M A TTORNE Y8 United States Patent 3,527,395 EXPLOSIVELY ACTUATED FASTENING TOOL John E. Jackson, Beachwood, and James F. Boehm,

Brookpark, Ohio assignors to Oglebay Norton Company, Cleveland, Ohio, a corporation of Delaware Filed Oct. 31, 1966, Ser. No. 590,802 Int. Cl. Bc 1/12 US. Cl. 227-10 8 Claims ABSTRACT OF THE DISCLOSURE An improved powder actuated fastening tool is adapted to be mounted on one end portion of an elongated support member to facilitate the attaching of insulating panels to a wall of an ingot mold. A locking assembly is provided for holding the fastening tool in a cocked condition to enable the tool to be remotely actuated by a mechanism mounted on the support member. In addition, the locking assembly insures that parts of the barrel assembly of the fastening tool are not separated if an impact or driving member should strike the barrel assembly.

The present invention relates to explosively actuated fastening tools, and in particular relates to explosive, powder actuated fastening tools for driving fastener pins for attaching insulating panels to a wall of an ingot mold to form a hot top therein.

An important object of the present invention is to provide a new and improved explosive, powder actuated fastening tool for driving a fastener pin for attaching one member to another, such as an insulating panel to a wall of an ingot mold, and which is of a highly practical, safe and durable construction and which includes a support and actuating arrangement to enable the fastening tool to be supported and actuated from a location remote from the tool.

Another object of the present invention is to provide a new and improved explosive, powder actuated fastening tool for driving a fastener into a structure and which includes a support housing, a barrel assembly slidably supported by said support housing and having one end which is adapted to receive a fastener pin and the other end which is adapted to receive an explosive cartridge and a movable impact member slidably supported within the barrel assembly for driving said fastener pin into said structure when said cartridge is fired, and wherein the impact member is of a constuction such that it is capable of withstanding repeated firings without breaking and has a longer life than known impact member constructions heretofore employed.

A further object of the present invention is to provide a new and improved explosive, powder actuated fastening tool of the character described and wherein the barrel assembly includes a barrel and a muzzle threadably connected therewith at its forward end whereby the muzzle can be readily connected and disconnected from the barrel and is capable of withstanding the high impact force of the impact member to prevent separation of the muzzle from the barrel in the event that the impact member forcibly strikes the muzzle when the fastening tool is fired.

A still further object of the present invention is to provide a new and improved explosive, powder actuated fastening tool which includes a barrel assembly slidably supported by a support housing and which is movable relative thereto, and which includes a restraining means comprising cooperable elements carried by the barrel assembly and housing and with the element carried by the barrel assembly being adapted to engage the element 3,527,395 Patented Sept. 8, 1970 ice carried by the support housing to insure that separation of the barrel assembly from the housing does not occur in the event that the impact member forcibly strikes a part of the barrel assembly.

Another object of the present invention is to provide a new and improved explosive, powder actuated fastening tool having a barrel assembly slidably supported by a support housing and which is movable relative to the support housing between a cartridge receiving position and a second position in which it cocks an actuating mechanism for actuating the powder cartridge and which includes a locking means comprising cooperable elements carried by the barrel assembly and support housing for locking the barrel assembly in its second position to enable the tool to be pre-cocked before being fired and to insure that separation of the barrel assembly from the support housing does not occur in the event the impact member forcibly strikes a part of the barrel assembly.

The present invention further resides in certain novel constructions and arrangement of parts, and further objects and advantages thereof will be apparent from the following detailed description of an illustrated embodiment of the present invention made with reference to the accompany drawings forming a part of the present specification and in which similar reference numerals are employed to designate corresponding parts throughout the several views, and in which:

FIG. 1 is a side elevational view of one embodiment of a fastening tool of the present invention;

FIG. 2 is a view similar to FIG. 1 but with certain parts thereof shown in axial cross section and in a different position;

FIG. 3 is an enlarged fragmentary bottom plan view of part of the fastening tool shown in FIG. 2 and looking in a direction of the arrows 33;

FIG. 4 is an enlarged fragmentary elevational view of part of the fastening tool shown in FIG. 2;

FIG. 5 is a fragmentary rear elevational view of another embodiment of an explosively powder actuated fastening tool; and

FIG. 6 is a fragmentary side elevational view of the fastening tool shown in FIG. 5.

Although a novel explosive powder actuated fastening tool of the present invention could be used for driving various types of fasteners into a structure, the fastening tool is particularly useful for driving fasteners to attach insulating panels or liners to an inside wall portion at the upper end of an ingot mold to form a hot top. Hot tops are used to maintain a supply of metal in a molten state at the upper end of an ingot mold for supplying molten metal to the mold to fill up the spaces created due to shrinkage of the metal as it cools and solidifies in the mold.

As representing one embodiment of the present invention, FIGS. l4 of the drawings show an explosive, powder actuated fastening tool 10. The fastening tool 10 is in the form of a gun and comprises, in general, a support or body portion 21 including a handle 22 and a support housing 23 secured to the body portion 21 for slidably supporting a barrel assembly 24. The barrel assembly 24 at its forward end is adapted to telescopingly receive a fastener 25 and at its opposite rearward end is adapted to receive a blank cartridge or powder cap charge 26. The tool 10 further comprises a firing pin actuating mechanism 27 for actuating or firing the cartridge 26 and an impact or drive member 30 slidably carried by the barrel assembly 24 and which is driven by the expanding gas energy of the fired cartridge to drive the fastener pin 25 into a wall 29 of an ingot mold to secure an insulating liner 31 thereto to form a hot top, and in a manner well known to those skilled in the art.

The support housing 23 for slidably supporting the barrel assemly 24 is annular and has an axially extending opening 32 therein for slidably receiving the rearward end, i.e., the left end as viewed in FIG. 1, of the barrel assembly 24. A support housing B further has a side opening 33- in communication with the axially extending opening 32 to enable a blank cartridge 26 to be positioned within the rearward end of the barrel assembly 24 and ejected therefrom after being fired.

The barrel assembly 24 is telescopingly received Within the opening 32 in the support housing '23 and includes an annular generally cylindrical barrel 35 and a muzzle 36 threadably connected to the forward end, i.e., the right end as viewed in FIG. 2, of the barrel 35. The barrel 35 and the muzzle 36 have axially extending through central openings 37 and 38 therethrough. The opening 37 has a rearward portion 37a along the rearward end of the barrel 35 which is of a diameter so as to freely slidably receive the blank cartridge 26, which may be of any conventional or suitable type, and a forward end portion 37b along the forward or remaining portion of the barrel which is of a larger diameter and slidably receives the impact or drive member 30.

The impact member 30 for driving the fastener into the wall 29 of the mold comprises a piston portion 40, a plunger portion 42 and an intermediate portion 43, formed integral with each other. The piston portion 40 is slidably received within the forward portion of the opening 37 and its inner end is adapted to abut an annular radially extending shoulder 44 formed at the junction of the different diameter openings 37a and 37b. The plunger portion 42 extends forwardly of the piston portion 40 and is slidably received within the opening 38 in the muzzle 36. The plunger portion 42 has a uniform or substantially uniform diameter or cross-sectional shape throughout its length, the diameter of the plunger portion 42 being substantially less than the diameter of the piston portion 40 and the axial length of the plunger portion 42 being substantially greater than the axial length of the piston portion 40. The intermediate portion 43 is axially tapered so that its diameter progressively increases proceeding from the rearward end of the plunger 42 toward the forward end of the piston portion 40 to provide a substantially gradual transition between the diameters or cross-sectional shapes of the plunger portion 42 and the piston portion 40. Thus, there is a distribution of stress over a substantial area when the inertia of the piston portion 40 is suddenly halted as the fastener pin 25 is driven into the wall 29 of the ingot mold. A suitable annular seal ring 45 disposed within an external circumferentially extending groove in the piston portion 40 is provided for effecting a gas pressure seal between the piston portion 40 and the barrel 35.

The barrel assembly 24 is slidably connected to the support housing 23 for movement relative thereto between a forward position, as shown in FIG. 1, in which the barrel assembly 24 is extended to unblock the opening 33 to permit a cartridge 26 to be placed within the rearward portion of the opening 37 at the rearward end of the barrel 35 and a first rearward position, as shown in FIG. 2, in which the side wall of the barrel 35 blocks the opening 33 and prevents access to the cartridge in the opening 37a. The barrel assembly 24 is also movable relative to the housing 23 from its first rearward position in a leftward direction, as viewed in FIG. 2, toward a second rearward position, as shown in FIG. 6, during which it cocks the actuating mechanism 27 to enable the blank cartridge to be fired, and in a manner to be hereinafter more fully described. To this end, the barrel assembly 24 is provided with a slot 50 and the support housing 23 carries a radially extending pin 51 threadably connected thereto and which has an inner end which is freely received within the slot 50. The slot 50 may be said to be generally Z-shaped and comprises a first axially extending portion 52, a circumferentially extending portion 53 and a second axially extending portion 54. When the barrel assembly 24 is in its forward position, as shown in FIG. l, the pin 51 is in engagement with the rearward end '55 of the first axially extending slot portion 52. When the barrel assembly is in its first rearward position, the pin 51 is disposed within the circumferentially extending portion 53 of the slot 50 and when the barrel assembly is in its second rearward position the pin is in engagement with the forward end 56 of the second axially extending slot portion 54. The provision of the pin and slot connection between the support housing 23 and the barrel 24 guides the movement of the barrel assembly 24 and connects the barrel assembly 24 and housing 23 together to prevent separation thereof.

The actuating mechanism 27 for actuating or firing the cartridge 26 may be of any suitable or conventional construction, and since it does not per se form a part of the present invention it will not be described in detail. Suifice it to say that the actuating mechanism comprises a spring biased firing pin 57 carried by the housing 23 and which is releasably connected via a movable pawl 58 to a spring biased cocking slide 59. The firing pin 57 is movable to a cocked position in opposition to the biasing force of its spring by the cocking slide 59 when the latter is engaged and moved toward the left, as viewed in FIG. 2, in opposition to the biasing force of its return spring 59a by the barrel 35 upon the barrel assembly 24 being moved toward the left from its first rearward position toward its second rearward position. Sufiice it further to say that the actuating mechanism 27 comprises a trigger 60 which is pivotally connected at its upper end via a pivot pin 61 to the housing 23 and which engages the pawl 58 to move the same upwardly and release its operative connection with the cocking slide 59 when pulled back in the direction of the arrow 62 to allow the spring biased firing pin to move forwardly from its cocked position and strike the cartridge 26 to actuate or fire the same.

From the foregoing, it should be apparent that when it is desired to drive a fastener into the wall 29 of the mold, the barrel assembly 24 is first moved forwardly to its forward position, as shown in FIG. 1. With the barrel assembly 24 in this position the cartridge 26 is inserted through the access opening 33 and into the rearward portion 37a of the opening 37 at the rearward end of the barrel 35. The barrel assembly 24 is rotated and then moved in a rearward direction from its forward position to its first rearward position in which it blocks the opening 33, as shown in FIG. 2. The muzzle 36 of the tool 10 is then telescoped over the fastener 25, which in the illustrated embodiment is shown as a preset fastener which is already afiixed to the insulating liner 31, until the muzzle engages the insulating liner 31. The support housing 23 of the tool 10 is then pushed in a forward direction toward the insulating liner 31 to cause the barrel assembly 24 to move rearwardly relative thereto from its first rearward position toward its second rearward position to cock the actuating mechanism 27. The tool 10 is then held in this latter position and the trigger 60' is pulled back to release the pawl 58 from the cocking slide 59 to enable the spring biased firing pin 57 to move in a forward direction and strike the cartridge 26 with a mechanical impact blow to fire the same. The energy generated when the blank cartridge 26 is fired is transmitted through the opening 37a and against the left end of the piston 40 of the impact member 30, as viewed in FIG. 2, to cause the latter to be rapidly moved toward the right which in turn causes the plunger portion 42 thereof to drive the fastener into the Wall 29 of the mold.

After the fastener has been driven into the wall 29 of the ingot mold, the tool 10 is retracted and the barrel assembly 24 is moved in a forward direction toward its forward position to uncover the opening 33. A suitable or conventional ejector mechanism 65 carried within the housing 23 can be provided to eject the case of the cars tridge through the opening 33 and clear of the tool as the barrel 24 moves toward its forward position.

One of the important features of the explosively actuated fastening tool 10 of the present invention is the novel construction of the impact or drive member 30. It has been found that by employing an impact or drive member wherein the plunger portion thereof is of a uniform or substantially uniform diameter throughout its length that the strength and life of the impact member is greatly increased over known impact member constructions in which the plunger portion is stepped. Moreover, the strength and life of the impact member is further enhanced by making the piston and plunger portions integral with each other and by providing a tapered intermediate portion to provide a substantially gradual transition between the diameter of the plunger portion and the diameter of the piston portion. This eliminates points of high stress concentration.

Another feature of the present invention is the provision of the threaded connection between the muzzle 36 and the forward end of the barrel 35. It has been found that such a connection provides a high strength connection and prevents the muzzle 36 from separating from the barrel 35 in the event the impact member 30 is forcibly driven against the rearward end of the muzzle 36 as a result of the tool 10 being free fired without the muzzle 36 being positioned against a solid member, and without a fastener positioned between the impact member and a solid structure. The inner end of the pin 51 would be sheared by the piston portion 40' during such movement. The advantage of the threaded connection is that not only can the muzzle 36 be readily connected to and disconnected from the barrel 35, but that it also functions as a safety feature and eliminates any need for a separate restraining arrangement to prevent separation between the muzzle and barrel in the event the impact member is driven against the muzzle. The bottoms or roots of the external threads on the muzzle and the internal threads in the barrel are preferably rounded so as to minimize stress concentration and thus, further increase the strength of the threaded connection.

Provision is made in the form of a restraining means, generally desigated by reference numeral 70, to prevent separation of the barrel assembly 24 from the support housing 23 in the event that the intermediate portion 43 of the impact member 30 forcibly strikes the muzzle 36 when the tool is fired. This would occur if the tool is fired without the muzzle being positioned closely adjacent or against the insulating panel 31. Since the only positive connection between the barrel assembly 24 and the support housing 23 is via the pin 51, the force exerted by the portion 43 of the impact member upon striking the muzzle 36 which in turn would be transmitted to the barrel in the event the tool is fired without the muzzle thereof being positioned closely adjacent or against a solid structure would cause the barrel assembly 24 to be moved forwardly and in most cases shear the pin 51 and separate from the housing 23. If the barrel were to be propelled from the housing 23, it could strike someone and cause injury.

The restraining means 70 functions as a safety device and comprises a pair of cooperable elements 71, 72 respectively carried by the support housing 23 and the barrel assembly 24. The elements 71, 72 engage one another to restrain forward movement of the barrel assembly 24 relative to the housing 23 should the portion 43 of impact member 30 engage the muzzle 36 in the event the tool 10 is fired without the muzzle being positioned against a solid structure. The element 71 is a radially extending pin threadably secured to a collar 73 which in turn is fixed in any suitable manner to the forward end of the support housing 23. The element 72 is L-shaped with one leg thereof extending axially of the barrel assembly 24 and being threadably secured at its forward end to a collar 75 suitably fixed to the forward end of the barrel 35. The other leg of the L-shaped element 72 extends transversely of the barrel assembly 24 and is adapted to be positioned or hooked behind the pin 71. The L-shaped element 72 is movable from a position in which it is hooked behind the pin 71 to a position in which it is not hooked behind the pin 71 by rotating the barrel assembly 24 relative to the housing 23 when the pin 51 is disposed within the circumferentially extending slot portion 53 of a slot 50. The provision of the Z-shaped slot 50 insures that the L-shaped restraining element 72 is hooked behind the pin 71 prior to moving the barrel assembly 24 from its first rearward position toward its second rearward position to cock the actuating mechanism 27.

In the event the tool 10 is fired without the muzzle 36 thereof being positioned against or closely adjacent the insulating liner 31, the L-shaped element 72 will engage the pin 71 to prevent movement of the barrel assembly 24 in a forward direction relative to the housing 23 upon the portion 43 of the drive member 30 being driven against the muzzle 36. Separation of the muzzle 36 from the barrel 35 is prevented as described above due to the high strength threaded connection therebetween.

Referring to FIGS. 5 and 6 of the drawings another embodiment of a fastening tool is there shown, and generally designated by reference numeral 78. The fastening tool 78 is of an identical construction to the fastening tool 10 except that it includes a novel support means '79 for supporting the tool 10 from a remote location and -a novel actuating mechanism 80 operatively connected with the trigger 60 of the actuating mechanism 27 for actuating the latter from a remote location. Moreover, the tool 78 includes a locking means 81 for locking the barrel assembly 24 in its firing position to enable the actuating mechanism of the tool 78 to be pre-cocked. Identical or similar parts of the fastening tool 78 will be given the same reference numerals as the corresponding parts of the fastening tool 10 shown in FIGS. 14.

In the fastening of insulating liners 31 to the upper end of mold wall 29 to form a hot top, it is necessary to position the gun part of the fastening tool 78 down inside the mold. This is often quite inconvenient. By employing the novel support and actuating arrangement shown in FIGS. 5 and 6, the gun part of the fastening tool can be readily and easily positioned in the mold.

The support means 79 comprises a hollow vertically extending support member 82 having a slanted lower end portion 83 which is suitably secured to the handle 22 of the gun part as by bolts 85. The support member 82 at its upper end is provided with a horizontally disposed handle 85 and intermediate its ends the support member is also provided with a horizontally extending handle 86. By grasping the handles 85 and 86 the operator by standing above the mold can support the gun part and can readily guide and telescope the muzzle 36 over the fastener 25 carried by the insulating liner 31.

When the tool 78 is so supported and has been precocked, the remote actuating mechanism 80 can be actuated to cause the trigger 60 to be pulled back to release the pawl 58 from the cocking slide 59 to enable the firing pin 57 to move in a forward direction and fire the cartridge 26. The actuating mechanism 80 comprises a member 90 having one end pivotally connected to a downwardly extending portion 91 of the handle 86 and its other end slidably received through a slot 92 in the side wall of the hollow vertically extending support member '82. The member 90 at its other end is fixed to one end of a cable 93, the other end of the cable 93 being suitably fixed to a pin 94 which in turn is fixed to the trigger 60 at a location rearwardly of and spaced from its pivotal connection with the housing 23. The member 90 is normally biased in a downward direction to the position shown in the solid lines of FIG. 5 by a compression spring 96 having one end secured to and in abutting engagement with the handle 86 and the other end secured to and in abutting engagement with the member 90. The lower end of the slot 92 provides a stop for the member 90 as it is biased in a downward direction by the spring 96.

When the member 90 is moved in an upward direction toward its phantom line position shown in FIG. 5, the cable 93 is caused to be moved in an upward direction. Movement of the cable 93- in this direction causes the trigger 60 to be pulled "back which in turn causes the pawl 58 to be disengaged or released from the cocking slide 59 to enable the firing pin 57 to be moved in a forward direction to fire the cartridge 26.

The locking means 81 is effective to lock the barrel assembly 24 in its cartridge firing or second rearward position to enable the actuating mechanism of the tool 78 to be 'pre-cocked prior to lowering and positioning the gun part thereof in the mold and is effective to prevent separation of the barrel assembly 24 from the support housing 23 in the event the impact member 30 forcibly strikes the muzzle 36 as a result of the tool being free fired without the muzzle being positioned against a solid member or without a fastener being positioned between the impact member 30 and a solid structure. When the barrel assembly 24 is moved back from its first rearward position toward its second rearward position to cock the actuating mechanism 27, it moves in opposition to the biasing force of the cocking slide return spring 59a and the spring for the firing pin 57. The biasing forces of these springs tend to move the barrel assembly toward its first rearward position and away from its cartridge firing position.

The locking means 81 is operable to lock the barrel assembly 24 in its second rearward position and thus, enable the actuating mechanism 27 to be pre-cocked prior to lowering the gun part of the tool 78 into the mold. The locking means 81 comprises a pair of cooperable elements 100, 101 respectively carried by a support housing 2.3 and the barrel assembly 24. The element 100 is in the form of a collar which is fixed in any suitable manner to the forward end of a support housing 23. The element 101 is L-shaped with one leg 102 thereof extending axially of the barrel assembly 24 and being fixed to one end of a handle 103, the handle 103 in turn being pivotally connected by a pivot pin means 104 to a collar 105 suitably fixed to the forward end of the barrel 35 for movement about an axis extending parallel to the axis of the barrel 35. The other leg 106 of the L-shaped element 101 extends transversely of the barrel assembly and is adapted to be positioned or hooked behind the collar 100, i.e., disposed behind the radially extending rearward surface of the collar 100.

The L-shaped member 101 and handle 103 are rotatable about the axis of the pivot pin 104 between a first position, as shown by the phantom lines of FIG. 5, in which the leg 106 is not hooked or positioned behind the collar 100 and a second position, as shown by the full lines of FIG. 5, in which the leg 106 is positioned behind the collar 100. The collar 105 is provided with a pair of stop pins 107, 108 which abuttingly engage the handle 103 and limit its movement when the latter is rotated to move the leg 106 to its first and second positions, respectively.

When the barrel assembly 24 is to be moved forwardly or rearwardly relative to the support housing 23 between its forward and first rearward position, the handle 103 is rotated to its phantom line position shown in FIG. 5, which in turn causes the leg 106 to be moved from its second position toward its first position in which it is not hooked behind the collar 100. When the barrel assembly 24 is moved to its second rearward position in which it cocks the actuating mechanism 27, it can be locked in this position by merely rotating the handle 103 to the full line position shown in FIG. which in turn causes the leg 106 to be positioned behind the collar 100. This locks the barrel assembly in its second rearward position relative to the support housing 23 and thus, enables the gun part of the fastening tool 78 to be precocked and thereafter positioned into the mold and fired.

Moreover, the locking means 81 also functions as a safety device in the same manner that the restraining means 70, previously described, functions as a safety device. That is, the locking means 81 prevents separation of the barrel assembly 24 from the support housing 23 in the event the impact member 30 forcibly strikes the muzzle 36 as a result of the tool 78 being free fired while the muzzle 36 is not positioned against a member or in the event a fastener is not positioned between the impact member and a structure.

It will, of course, be understood that other types of locking means or arrangements could be employed for locking the barrel assembly 24 in its second rearward position in which it cocks the actuating mechanism 27 to enable the fastening tool 78 to be pre-cocked. For example, a locking arrangement could be provided in which the L-shaped member is carried by the barrel assembly 24 in a manner such that the L-shaped member would hook behind the trigger guard or other stationary member on the housing 23 when the barrel assembly is rotated relative to the support housing. Moreover, a toggle linkage could be used in connection with the L-shaped member and barrel assembly for moving the barrel assembly to pre-cock the tool without disturbing the locked position of the L-shaped member relative to the trigger guard and with the tool being pre-cocked when the two toggle links of the toggle linkage are in an on or slightly over center position.

From the foregoing, it should be apparent that the hereinbefore enumerated objects and others have been accomplished and that a new and improved explosively actuated fastening tool which is of a highly practical, safe and durable construction and which is especially adapted for use in driving fastener pins to attach insulator liners to walls of a mold to form hot tops has been provided. While the illustrated embodiment of the present invention has been described in considerable detail, it is hereby our intention to cover all constructions, modifications and arrangements which fall within the ability of those skilled in the art and in the scope and spirit of the appended claims.

Having described our invention, we claim:

1. An explosively actuated fastening tool for driving a fastener into a structure comprising a support housing having an opening therein, barrel means slidably carried by said housing and having an opening therein, said barrel means at one end being adapted to receive a fastener to be driven and at the other end being adapted to receive an explosive cartridge, said barrel means being movable relative to said support housing between a cartridge receiving position and a second position, an actuating mechanism for actuating said cartridge, an impact member slidably carried by said barrel means and movable relative thereto toward said one end upon actuation of said explosive cartridge to drive said fastener into said structure, said barrel means having a part in the path of movement of said impact member, and restraining means eflective to prevent separation of said barrel means from said support housing in the event said impact member strikes and shears said part.

2. An explosively actuated fastening tool, as defined in claim 1, and wherein said barrel means is rotatable relative to said support housing when in said second position, and wherein said restraining means comprises a pair of relatively movable cooperable elements, one of said elements being connected to said barrel means the other of said elements being connected to said support housing and extending transversely thereof, said one element having a hook portion which is movable between a first position in which it is not hooked behind said other element and a second position in which it is hooked behind said other element in response to rotation of said barrel means relative to said support housing when the former is in its second position.

3. An explosively actuated fastening tool, as defined in claim 2, and wherein said barrel means has a slot in its side wall and said support housing has a pin member fixed thereto which extends into said slot, and wherein said slot has an axially extending portion to enable said barrel means to be moved between its cartridge receiving position and said second position and a circumferentially extending portion at one end of said axially extending portion whereby said barrel means can be rotated relative to said support housing to move said one element between its first and second positions.

4. An explosively actuated fastening tool, as defined in claim 1, and wherein said impact member comprises a plunger portion, a piston portion at one end of said plunger portion, said piston portion having a substantially greater transverse dimension than said plunger portion, and wherein said barrel means comprises a barrel and a muzzle threadably connected to said barrel at said one end thereof, said muzzle having an opening therethrough for receiving said plunger portion, said piston portion being engageable with said muzzle to retain said impact member within said barrel means.

5. An explosively actuated fastening tool for driving a fastener into a structure comprising a support housing, barrel means slidably carried by said housing, said barrel means being movable relative to said support housing between a cartridge receiving position and a cartridge firing position, an impact member carried by said barrel means and movable relative thereto upon actuation of said explosive cartridge to drive the fastener into the structure, an actuating mechanism for actuating said cartridge including a yieldable member yieldably resisting movement of said barrel means to its cartridge firing position, and locking means for locking said barrel means in its firing position against the action of said yieldable member.

6. An explosively actuated fastening tool, as defined in claim 5, and wherein said locking means comprises a pair of relatively movable cooperable elements, one of said elements being connected to said barrel means and the other of said elements being fixed to said support housing,

said one element being rotatable and having a hook portion which is movable between a first position in which it is not hooked behind said other element and a second position in which it is hooked behind said other element to lock said barrel means in its second position in response to rotation of said one element.

7. An explosively actuated fastening tool as defined in claim 5 further including a member movable to actuate firing of said cartridge and means supporting said member at a location remote from said barrel means.

8. An explosively actuated fastening tool, as defined in claim 5, and wherein said actuating mechanism includes an actuating member movable between a cocked position and a second position in which it is effective to actuate said cartridge, spring means for biasing said actuating member toward its second position said barrel means being engageable with said actuating member and effecting movement of said actuating member from its second position toward its cocked position in opposition to the biasing force of said spring as it is moved toward its second position, and including an elongated support member for carrying said tool adjacent one end thereof and means carried by said support member and operatively connected with said actuating mechanism for releasing said actuating member for movement from its cocked position toward its second position.

References Cited UNITED STATES PATENTS 3,310,215 3/1967 Bostick 227-l32 XR 3,341,101 9/1967 Butler et al. 227-10 XR 3,348,751 10/1967 Henning 227l0 XR FOREIGN PATENTS 211,001 2/1924 Great Britain.

GRANVILLE Y. CUSTER, JR., Primary Examiner 

